Transcript of 'Families never forget': Police discuss breakthrough in cold case of missing woman

September sixth, 1970 was the last time anyone saw Donna Las. The 25-year-old South Lake Tahoe resident was on the job at the time.

She was working as a nurse at the Sahara Tahoe, which is a casino on the Nevada side.

That casino hotel is now the Golden Nugget. While the name has changed, what hasn't is the mystery surrounding Las' disappearance.

Old cases stay open till they're solved.

South Lake Tahoe Police Chief David Stevenson tells me a security supervisor at the hotel filed a missing persons report three days after Lassie went missing. For 50 years, she remained lost until now. The plaster County Sheriff's office says a skull found in 1986 off of Highway 20 near Interstate 80 has been identified as Lass. But what took so long?

At that time, the DNA testing technology wasn't advanced enough to get a sample.

Stevenson also says DNA from Lass's relatives was not collected until her sister gave a sample five years ago. Enter a new cold case team made up of people from the Plaster County sheriffs and district attorney's offices. Last week, the team sent the skull to the California Department of Justice, hoping new technology could ID it.

They had those remains sampled for DNA. It was processed, run through the system, and they were... Cal, DOJ was able to get a hit on those remains based on that familial DNA that was uploaded.

It matched with Las, but it's still unclear how she died.

It hasn't been proven to be a homicide at this point, but we're obviously treating it that way.

What happens next? Even after more than five decades since Donna Lass was last seen here, there are still no suspects, but police say they won't stop searching.

From here on, it's just a matter of following up on any leads that may come in.

Stevenson hopes Las's family finds some closure knowing her fate, but understands there are more questions they want answered.

Obviously, it was a long time ago, but families never forget. It never gets old. It never goes away. They never heal. That unknown is very painful for them.

Reporting from South Lake Tahoe, Orca Manor KCRA 3 news.

Thanks for watching. Stay updated about breaking news and top stories on the BBC News app, or follow us on social media.